rahul taiwala wrote:use paint method instead of paintComponent and its working fine.....

This solution sounds very wrong. Sorry but it sounds like you're fixing the wrong thing, but I can't say what since I can't get your code to compile or run due to missing classes. One problem I see that is not causing your main question but can bite you later is that you have program logic within your paint/paintComponent method as indicated by my comment // **** here ****:

and program logic should not be in this method as you do not have full control as to when or if it will be called. Also it is strange to see a repaint() call within a paint/paintComponent method. If the JVM weren't smart, this would cause an infinite recursive cycle.